Johnson captained England to their last RBS 6 Nations clean sweep in 2003, which was coincidentally sealed with a thumping victory at the old Lansdowne Road. But that England team only hit the heights in 2003 after experiencing the pain of three previous failed Grand Slam attempts.

Croft insists there is no better man than Johnson for England to have in the trenches, and said: "It will be an emotionally-charged day in Ireland. We know it is a Grand Slam game but we have to got to keep our heads and not get too overexcited."

He added: "Martin Johnson's experience will be absolutely huge. He knows the emotions we will be feeling this week leading up to the game, he knows he will need to step in and calm the boys down now and again.

"But in the changing room before the game he will be just as bad as the rest of the players because he still has that playing instinct at heart and the boys like to see him show that emotion.

"He gets as excited as a player does. The raw emotion he had when he was playing, he brings that into the changing room with the things he says. It is great to see the manager have the same sort of emotions leading up to such a great game."

Croft, fit again after suffering a fractured shoulder, came off the bench to score England's only try against Scotland as they set up a Grand Slam shot.

It was an ugly, error-ridden, disjointed performance and England are under no illusions they will need to improve to win in Ireland.

"We have to fight as if this is a cup final, which effectively it is," said James Haskell, who was man of the match against Scotland.

"The last couple of games against Ireland were incredibly tough. I remember in 2009 losing by a point (14-13) in Croke Park and then last year just missing out to the Irish at Twickenham (20-16). Ireland will be bitter after the controversial nature of their loss against Wales at the weekend."